Fuse plug for pressure cookers



p 1939- E. cs. GRUNDSTROM 73,999

FUSE PLUG FOR PRESSURE COOKERS Or iginal Filed Jan. 2, 1937 Patented Sept. 26, 1939 UNITED STATES FUSE PLUG FOB PRESSURE COOKEBS Erik G. Grundstrom, Chicago,

Advance Aluminum Castings lll., aslignor to Corps Chicago,

Ill., a corporation of Illinois Original application Jan 118,881. Divided an nary 2, 1937. Serial No.

d this application March 8, 1939, Serial No. 260,465

9 Claims.

The present invention relates to improvements in fuse plugs for pressure cookers.

The present application is a. division of application Serial No. 118,881, filed January 2, 1937,

5 by the present applicant.

The description of the present invention may be prefaced by the statement that in pressure cookers a vessel containing the material to be cooked is tightly sealed and heated to a sufliciently high temperature to cause the generation of steam either from the moisture of the material being cooked or from other liquid contained within said vessel. After a predetermined pressure has been attained, the vessel may be removed from the source of heat and the material therein subjected to temperature and pressure conditions for a predetermined length of time.

An object of the present invention is to provide an improved pressure cooker having novel fuse means for protecting said cooker against excessive temperature conditions, which fuse means is provided with guard means for preventing the spreading of the material within the cooker over the adjacent region.

A further object is to provide an improved pressure cooker well adapted to meet the needs of ordinary culinary service in the home or in a restaurant or the like.

Further objects will appear as the description proceeds.

Referring to the drawing- Figure 1 is a top plan view of a pressure cooker embodying the principles of the present invention; and

35 Figure 2 is a vertical sectional view on an enlarged scale.

The numeral I indicates a vessel. Said vessel I0 is provided with the elliptical opening I2 bounded by the flange I3. The cover II is pro- 40 vided with a flange I4 adapted to underlie the flange I3, the gasket I5 being provided between said flange I4 and said flange I3. As shown in Figure 1, the cover I I is provided with a protuberance I6, preferably located at one extremity of the long axis of said cover, adapted to fit into a. corresponding recess in the adjacent portion of the vessel I0. Said cover II at the other extremity of its long axis is provided with the protuberance Il fitting into a corresponding recess in the 5 vessel I0. Said protuberances I6 and Il are preferably of different sizes, so that the operator of the pressure cooker will be guided by said pro tuberances in placing the cover II in proper position relative to the vessel ID. The gasket I5 is recessed to correspond to the protuberances I6 and Il. The flange I4 on its upper surface is provided with a bead Ila extending around the cover, which bead is adapted to embed itself into the gasket I5 when pressure is exerted between the flanges i3 and ll, as will be explained presently, thereby greatly improving the sealing action of the gasket, IS. A further advantage of the bead Ila is that, since the gasket IE will in service receive a more or less permanentindentation from the bead Ila, said bead and said in- 5 dentation will constitute indicating means to insure the same setting of the gasket I5 with reference to the flange I4 at all times. Particularly in cooperation with the protuberances I8 and Il, the flanges .I3 and I 4 and the gasket I5 will always have the same setting relative to one another, thereby avoiding the faults of some gaskets that after they lose their original resiliency they lose their efliciency due to the fact that it is not possible to always reset them in correct relationship with reference to the members between which they are to perform their sealing functions.

Mounted centrally of the cover I I is the upstanding threaded stud I8 having a handle l9 flxed to its upper extremity. Said handle I9 is preferably of heat insulating material, whereby the cover II and the vessel III may be readily manipulated Underlying said handle I9 is the spring 20 rotatable about the stud I8 and having two extremities adapted to bear against the upper surface of the flange I3 of the vessel I0. Said extremities of said spring 20 are adapted to abut against abutments 2I-2I formed integral with said flange I3 oi. the vessel III. The upper surface of the flange I3 adjacent to the abutments 2 I-2I may be slightly raised, as indicated by the numerals 22-22, whereby as the spring 20 is turned away from its operative position as shown in Figure 1, said spring 20 will be quickly released without binding or unnecessary scratching of the surface of the flange I3.

The stud I8 which carries the handle- I9 is screw-threaded within thecover II, and a spring 23 is provided between the upper side of the cover II and the under side of the spring 20 for holding the extremities of the spring 20 away from the; cover I I when said cover is removed from the vessel I II. The spring 23, by holding the member 20 against the lower extremity of the handle' lil, facilitates the handling of the entire cover assembly, as the distance between the cover and the lower extremity of the handle I9 will vary considerably. The handle I9 and its stud I8 are threaded into the nut 24, which nut is externally threaded within the boss 25 extending downwardly from the under side of the cover II. The upper surface of the head 24a of the nut 24 is provided with the circular bead 24b adapted to embed itself into the gasket 24c.

'Ihe numeral 26 indicates as a whole a fuse plug carried by the cover II. Said fuse plug includes the fusible element 21 mounted within the plug member 28, which plug member 28 is externally screw-threaded and is adapted to be mounted within a correspondingly tapped hole 29 in 50 possible to screw in the fuse plug 2' from the wrong direction. A gasket 30 is provided between the head Na and the cover I I for providing a tight joint. The upper surface of the head 290 will be provided with an annular bead 2911 which will become embedded in the gasket III to provide a tight seal without requiring excessive tightening effort on said plug 2'. As clearly shown in Figure 2, the fusible element 21 is tapered, the larger extremity thereof being uppermost. By

reason of this construction, in the event that an excessive temperature is developed in the cooker, the fusible element 21 will first soften and be released from the plug member 28, permitting the escape of steam from within the vessel It. By reason of this construction the melting of the fusible element 211s avoided.

The numeral 3| indicates a shield covering the upper extremity of the hole 29. Said shield is releasably held in position by means of the spring 23 and is releasably held relative to the hole 29 by a pair of struck out portions 32-32 adapted to seat within corresponding recesses in the upper side of the cover II. By reason of the shield 3|, in the event that the fusible element 21 is released, juices and other fluid materials within the vessel ill will be prevented from spurting over theregion adjacent to the vessel Ill, but will be defiected and merely flow downwardly on the cover I I and along the sides of the vessel l0.

Though a preferred embodiment of the present invention has been described in detail, many modifications will occur to those skilled in the art. It is intended to cover all such modifications that fall within the scope of the appended claims.

What is claimed is- 1. In a pressure cooker, in combination, a vessel, a cover therefor, said cover having a rim portion adapted to contact on the inner wall of said vessel, a holding member adapted to contact with the outer surface of said vessel for holding said cover in position, spring means for holding said holding member away from said cover, a fuse plug in said cover, said fuse plug including a fusible element, and a shield for the aperture resulting when said fusible element gives way in response to temperature conditions, said spring member being positioned to hold said shield in shieldi position. 7

2. In combination, a vessel, a cover therefor, said cover having a rim portion adapted to fit on the inside surface of said vessel, a bowed hold-' ing member for holding said cover in position, a spring meniber between said cover and said holding member, a handle for said cover, said handle being movable to control the tension of said bowed member, a fuse plug in said cover, and a shield for said fuse plug, said spring member being positioned to hold said shield in shielding position.

3. In a pressure cooker, in combination, a vessel, a cover therefor, a holding member for holding said cover in position on said vessel, a fuse plug in said cover, said fuse plug including a fusible element, said fusible element being of tapering conformation in cross: section and having its greatest cross sectional area toward the outresulting when said fusible element gives way in response to temperature conditions, said holding means being positioned to hold said shield in shielding position.

4. In a pressure cooker. in combination, a vessel, a cover therefor, a holding member for holding said cover in position on said vessel, a fuse plug in said cover, said fuse plug including a fusible element, said fusible element being of tapering conformation in cross section and having its greatest cross sectional area toward the outside of said cover, and a shield for the aperture resulting when said fusible element gives way in response to temperature conditions, said holding means being positioned to hold said shield in shielding position, said shield and said cover having cooperating projections and depressions for locating said'shield.

5. A fuse plug adapted to be disposed in the cover of a pressure vessel, said fuse plug including a threaded plug member adapted tq be screwed into said cover only from the under side thereof, and a fusible element within said plug, said fusible element being of tapering conformation increasing in diameter toward the outside of said cover.

6. A fuse plug adapted to be disposed 'in the cover of a pressure vessel. said fuse plug including a threaded plug member adapted to be screwed into said cover only from the under side thereof, a fusible element within said plug, said fusible element being of tapering conformation increasing in diameter toward the outside of said cover, and a shield overlying the outer end of said fusible element.

'7. In combination with the cover of a pressure vessel, a threaded plug positioned in an aperture which extends through said cover, said plug and cover being so formed that said plug may be threaded into said cover only from the inner side of said cover, said plug having a head, the under side of said head being provided with an annular bead, and a gasket between the head of said plug and said cover, said bead being adapted to be embedded in said gasket.

8. In combination with the cover of a pressure vessel, a threaded plug positioned in an aperture which extends through said cover, said plug and cover being so formed that said plug may be threaded into said cover only from the inner side of said cover, said plug having a head, the under side of said head being provided with an annular bead, a gasket between the head of said plug and said cover, said bead being adapted to be embedded in said gasket, and a fusible element in said plug, said fusible element being of tapering conformation having its larger diameter adjacent to the outside of said cover.

9. In combination with the cover of a pressure vessel, a threaded plug positioned in an aperture which extends through said cover, said plug and cover being so formed that said plug may be threaded into said cover only from the inner side of said cover, said plug having a head, the under side of said head being provided with an annular bead, a gasket between the head of said plug and said cover, said bead being adapted to be embedded in said gasket, a fusible element in said plug, said fusible element being-of'tapering conformation having its larger diameter adjacent ing said fusible element.

ERIK G. GRUNDS'I'ROM 

